TM 9-2320-280-20-1REFERENCE INFORMATIONDead glowplugs draw virtually no current, butother parts of the vehicle are drawing somecurrent, up to 8 amps. If any glowplugs aredrawing any current, then the protectivecontrol box is probably OK.For a good description of how glowplugs cycleand how to check for proper cycling, refer topage 2-307.WARNINGDisconnect negative battery cable beforedisconnecting and reconnecting protectivecontrol box harness.There is battery voltage at the PCB at all times.Failure to disconnect battery cable will result indamage to equipment or injury to personnel.If most or all of the glowplugs are bad, you mayalso have a problem with the protective controlbox or the glowplug controller which causedthem to go bed (usually they burn out frombeing on too long or not turning off at all). Afterreplacing the bad glowplugs, rerun theglowplugs test chain paying special attention tothe glowplugs cycling, especially that they turnOFF when they should.Replace glowplugs, wires, or harness, refer to(para 3-38).1.2.3.Disconnect ALL the glowplugs.Disconnect the negative battery cable. Disconnect the PCBconnector harness from the PCB. Reconnect the negativebattery cable. Measure the resistance between pin Din theengine connector harness of the protective control box andground. There should NOT be continuity (resistance readingoff-the-scale). If there is continuity, repair or replace theharness.Repeat the following for each glowpluga.b.c.Reconnect the wiring harness to the glowplug while yourepeat the resistance measurement described in step 2.When you reconnect the wire to the glowplug, theresistance should drop to between 1 and 2 ohms(glowplugs are typically 1.6 ohms).If step a passed;disconnect the glowplug again, making sure the resistancegoes off-scale again. Repeat step a for the next glowplug.If step a failed;then either the glowplug or its wire is no good. Take thewire off the glowplug again and measure the resistancefrom the glowplug to the engine block. If the resistance is1-2 ohms, then the cable is no good, otherwise replacethe glowplug and check the cable for continuity, just to besure.4.Reconnect the PCB and all wires.2-309